text: # Copyright (C) 2003-2007, 2009, 2010 Nominum, Inc.
  #
  # Permission to use, copy, modify, and distribute this software and its
  # documentation for any purpose with or without fee is hereby granted,
  # provided that the above copyright notice and this permission notice
  # appear in all copies.
  #
  # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
  # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
  # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  
  import dns.exception
  import dns.rdata
  import dns.rdatatype
  import dns.name
  
  class NXT(dns.rdata.Rdata):
      """NXT record
  
      @ivar next: the next name
      @type next: dns.name.Name object
      @ivar bitmap: the type bitmap
      @type bitmap: string
      @see: RFC 2535"""
  
      __slots__ = ['next', 'bitmap']
  
      def __init__(self, rdclass, rdtype, next, bitmap):
          super(NXT, self).__init__(rdclass, rdtype)
          self.next = next
          self.bitmap = bitmap
  
      def to_text(self, origin=None, relativize=True, **kw):
          next = self.next.choose_relativity(origin, relativize)
          bits = []
          for i in xrange(0, len(self.bitmap)):
              byte = ord(self.bitmap[i])
              for j in xrange(0, 8):
                  if byte & (0x80 >> j):
                      bits.append(dns.rdatatype.to_text(i * 8 + j))
          text = ' '.join(bits)
          return '%s %s' % (next, text)
  
      def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
          next = tok.get_name()
          next = next.choose_relativity(origin, relativize)
          bitmap = ['\x00', '\x00', '\x00', '\x00',
                    '\x00', '\x00', '\x00', '\x00',
                    '\x00', '\x00', '\x00', '\x00',
                    '\x00', '\x00', '\x00', '\x00' ]
          while 1:
              token = tok.get().unescape()
              if token.is_eol_or_eof():
                  break
              if token.value.isdigit():
                  nrdtype = int(token.value)
              else:
                  nrdtype = dns.rdatatype.from_text(token.value)
              if nrdtype == 0:
                  raise dns.exception.SyntaxError("NXT with bit 0")
              if nrdtype > 127:
                  raise dns.exception.SyntaxError("NXT with bit > 127")
              i = nrdtype // 8
              bitmap[i] = chr(ord(bitmap[i]) | (0x80 >> (nrdtype % 8)))
          bitmap = dns.rdata._truncate_bitmap(bitmap)
          return cls(rdclass, rdtype, next, bitmap)
  
      from_text = classmethod(from_text)
  
      def to_wire(self, file, compress = None, origin = None):
          self.next.to_wire(file, None, origin)
          file.write(self.bitmap)
  
      def to_digestable(self, origin = None):
          return self.next.to_digestable(origin) + self.bitmap
  
      def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
          (next, cused) = dns.name.from_wire(wire[: current + rdlen], current)
          current += cused
          rdlen -= cused
          bitmap = wire[current : current + rdlen]
          if not origin is None:
              next = next.relativize(origin)
          return cls(rdclass, rdtype, next, bitmap)
  
      from_wire = classmethod(from_wire)
  
      def choose_relativity(self, origin = None, relativize = True):
          self.next = self.next.choose_relativity(origin, relativize)
  
      def _cmp(self, other):
          v = cmp(self.next, other.next)
          if v == 0:
              v = cmp(self.bitmap, other.bitmap)
          return v
  